1. Field of the Invention
The present invention relates to a visual sensor calibration method of calibrating a visual sensor in a robot system, and more particularly, to a visual sensor calibration method of calibrating a plurality of cameras or the like.
2. Description of the Related Art
In current practice a robot system is provided with a visual function to enable it to pick up an image of a workpiece by using a camera or the like to determine the position of the workpiece, and thus carry out an operation such as assembling or palletizing or the like. Further, a plurality of cameras are used to accurately determine the position of a workpiece, or to correspond to a plurality of robots.
It is necessary to calibrate the relationship between a a robot coordinate system and a camera coordinate system, to accurately determine the position of a workpiece, and when a plurality of cameras are used, an exclusively designed jig is prepared and used.
Such a calibration jig is large, however, and the jig must be moved by jogging or a similar operation, to thereby pick up images thereof by a camera, resulting in a poor operability.
Further, because most calibration jigs are large, they incur high manufacturing costs and the like, and require a special installation space.
Furthermore, when a plurality of cameras are used, it is difficult to calibrate each camera.